2,2'-Dihydroxy-4-methoxybenzophenone

Chemical Properties

Light yellow powder. Freezing point 68℃, boiling point 170-175℃(0.133kPa), relative density 1.382(25℃).Solubility at 25℃(g/100g solvent): benzene 46.6, n-hexane 2.3, 95% ethanol 21.4, carbon tetrachloride 22.2, methylethyl ketone 55.3, plasticiser DOP 31.1, insoluble in water.

Application

Dioxybenzone is a compound used in sunscreen formulations to block out UVB and UVA harmful rays. Broad-spectrum sunscreens often contain a number of chemical ingredients that absorb UVA and UVB radiation. Many sunscreens contain UVA-absorbing avobenzone or a benzophenone (such as dioxybenzone, oxybenzone, or sulisobenzone), in addition to UVB-absorbing chemical ingredients (some of which also contribute to UVA protection).

Uses

benzophenone-8 (dioxybenzone) is an FDA-approved sunscreen chemical with uVA-absorption capabilities. It also can protect product degradation arising from uV-light exposure. It has an approved usage level of 3 percent in the united States.

Preparation

preparation by condensation of salicylic acid and m-methoxyphenol.

Definition

ChEBI: 2,2'-Dihydroxy-4-methoxybenzophenone is a member of benzophenones.

General Description

Dioxybenzone, also known as benzophenone-8, is an organic compound and a derivative of benzophenone used commercially in sunscreens. It absorbed UV-B and UV-AII rays. Dioxybenzone is an approved sunscreen ingredient in concentrations up to 3%.

Reactivity Profile

An alcohol and a ketone. Flammable and/or toxic gases are generated by the combination of alcohols with alkali metals, nitrides, and strong reducing agents. They react with oxoacids and carboxylic acids to form esters plus water. Oxidizing agents convert them to aldehydes or ketones. Alcohols exhibit both weak acid and weak base behavior. They may initiate the polymerization of isocyanates and epoxides. Ketones are reactive with many acids and bases liberating heat and flammable gases (e.g., H2). The amount of heat may be sufficient to start a fire in the unreacted portion of the ketone. Ketones react with reducing agents such as hydrides, alkali metals, and nitrides to produce flammable gas (H2) and heat. Ketones are incompatible with isocyanates, aldehydes, cyanides, peroxides, and anhydrides. They react violently with aldehydes, HNO3, HNO3 + H2O2, and HClO4.

Fire Hazard

Flash point data for 2,2'-Dihydroxy-4-methoxybenzophenone are not available. 2,2'-Dihydroxy-4-methoxybenzophenone is probably combustible.